The LM3S628-IQN50-C2T: That means TI is not actively promoting it for new projects, and the production window is finite. For existing designs already using this MCU, the independent channel still holds stock, but the clock is ticking on fresh TI fab runs.
50 MHz Cortex-M3 — enough for most control loops
The Cortex-M3 core runs at 50 MHz. The connectivity block includes I²C, SPI, SSI, Microwire, and UART/USART.
48-LQFP — hand-solderable, but watch the thermal
The package is a 48-pin LQFP with a 7x7 mm body (supplier device package 48-LQFP (7x7)). It is a hand-solderable footprint, fine for prototyping and rework.